Industrial large scale silicon nitride deposition on photovoltaic cells with linear microwave plasma sources

Microwave plasmas have some outstanding features like high charge carrier concentrations at ion- and electron energies below 10 eV, which predestine these plasmas for thin film deposition technologies requiring a non-remarkable ion impact. The plasma deposition of the passivating Si3N4-layers on multi-crystalline solar cells without formation of ion impact induced surface recombination centres is an example for such kind of process. By using the process gases SiH4, NH3 and H-2 a hydrogen rich plasma is generated resulting in excellent passivation properties of the silicon nitride layers on photovoltaic cells. In order to achieve stable plasma conditions on large-scale industrial deposition dimensions (150 nm/min at an area of 20 X 100 cm(2)) over long times, magnetic field enhanced linear microwave plasma sources based on the plasmaline principle were applied. Following, some results for this remote microwave PECVD of Si3N4 on multi-crystalline silicon solar cells are presented., (C) 2003 Elsevier Science B.V. All rights reserved.